The game worked perfectly ... once ... and now I can't even play it. It keeps saying that no save file is found ... even when I choose "New Game."
yea well what operating system are you using since you did not mention that in the first place, which is also equally unhelpful
also try running VisualBoyAdvance-M from another computer or a different OS platform such as Windows or MacOS
I run the VBA-M app from a folder or path with a "short" name that doesn't contain spaces in between (never using folders with really long names or paths), on SEVERAL Windows based computers and they all work correctly, including game saving & loading.